https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89922
--- Comment #2 from Antony Polukhin <antoshkka at gmail dot com> --- The estimation is very close to the actual result for the loop. But it does not take into the account the instructions before the loop that are eliminated due to unrolling. Some heuristic like "initializing the local variable with goes away for unrolled loops if the variable is rewritten in loop or if the variable is not used outside the loop"
